I am trying to implement DHCP. I opened a udp port with an IP of 0.0.0.0 and a netmask of 0.0.0.0. I can send out the discover packet but it does not receive the offer. Using a test application I sent various packets to the device.

This is for DCHP so all that is unknown hence the broadcasts. As stated to W5200 is configured with a source IP of 0.0.0.0 and a netmask of 0.0.0.0 at this time. The host PC sending the packet was was configured with a netmask of 255.0.0.0 when that trace was taken but class B and class C networks have also been tried with similiar results.

I have since downloaded the file W7200_AN_DHCP_SMTP_V111.zip and I do not see anything I am doing different.

I have them connected using a Hub. I was concerned the packets were not reaching the W5200 so I connected a second PC to the hub and ran the wireshark trace on that and it showed the packet. Also the light blinks when on the W5200 when I send the broadcast from the PC so it seems the packet is reaching the device.

Thanks for the trace. That at least is confirmation it is possible for the W5200 to receive the broadcast. I had already downloaded and reviewed the source you referred to. We are now going to try a W5200Emu module and put in the sample code, verify it works and then try to break it the same way to figure out the problem.

We are sure the hub is not dropping the packets. That is where the extra pc running wireshark is. We tried a direct connection to the pc first. We had aTCP loopback running with static ip before working on the dhcp.

We found the problem. UDP does not seem to work correctly if the MF (MAC Filtering bit) is set in the SN_MR register. The documentation should be updated to reflect this. Setting this bit seems like the correct think to do. Otherwise it seems you want promiscuous mode which I do not. It is strange that setting this changed the way it responded to IP addresses even though the MAC address was not changed. We dumped all the registers from the W5200-EVB and this was the difference. We were able to reproduce the problem in the W5200-EVB by setting this bit.